1. Field of the Invention
The present invention relates to a semiconductor device, in particular to a resin-sealed semiconductor device in which heat radiation from a package is improved.
2. Description of the Related Art
For high power consumption semiconductor devices which usually generate heat inside during operation, there has been proposed various methods of enhancing capability of radiating heat from a package.
For instance, a semiconductor device, as shown in FIG. 12, includes an island 102 on which a semiconductor element 101 is mounted, a lead frame 103 having an inner lead 104, and a heat spreader 106. The heat spreader 106, the island 104 and the lead frame 103 of the semiconductor device are fixed with a low melting point metal plating 105. In another case, a heat spreader and a lead frame are adhered to each other with an adhesive in Japanese Laid-Open patent application No. 5-36862.
However, such conventional resin-sealed semiconductor devices have their respective problems.
That is, in the above case where the island is fixed to the heat spreader with the low melting point metal plating, the low melting point metal plating is molten at the time of resin injection, so that the fixation is not secure. For that reason, the contact between the heat spreader and the island is sometimes incomplete. The case where the heat spreader and the island are adhered to each other using an adhesive has a drawback of rising in production cost due to expensiveness of the adhesive.